Intraocular lenses with customized add power

ABSTRACT

Intraocular lenses with a base optical power and a customized add power. The add power is customized based on at least one of ocular biometry of an individual, position of the intraocular lens in the eye and a preferred reading distance.

CROSS REFERENCES TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. § 119(e) of U.S.Provisional Patent Application No. 62/556,752, filed Sep. 11, 2017,which is incorporated herein by reference in its entirety.

BACKGROUND Field

This disclosure generally relates to lenses with optical add power.

Description of Related Art

Patients suffering from presbyopia can benefit from multifocal lensesthat are configured to provide distance vision correction as well asintermediate and/or near vision correction. Current multifocalintraocular lenses are offered in discrete add powers, that are fixedacross the complete spherical equivalent power range.

SUMMARY

The systems, methods and devices of the disclosure each have severalinnovative aspects, no single one of which is solely responsible for thedesirable attributes disclosed herein.

Presbyopic patients can benefit from multifocal lenses that can providevision correction for distance and near and/or intermediate vision.Various embodiments of intraocular lenses (IOLs) contemplated in thisapplication are configured to provide a spherical equivalent power fordistance vision correction and an add power for near and/or intermediatevision correction. The add power can be customized based on a patient'socular biometry and/or preferred reading distance.

An innovative aspect of this application is implemented in anintraocular lens for implantation in to the eye of a patient. Theintraocular lens is a multifocal optic having a spherical equivalentoptical power less than or equal to 50 Diopters and an optical add powercustomized for a patient's visual needs determined based on a positionof the intraocular lens when implanted in the eye of the patient, and aparameter of the patient's eye. The position of the intraocular lenswhen implanted in the eye of the patient can be the effective lensposition, the actual lens position or a combination thereof. Theeffective lens position can be calculated by Hoffer Q, Holladay I orHaigis formula. The actual lens position can be determined from arelationship between the anterior-chamber depth prior to the surgery andthe actual IOL position measured from the anterior cornea after thesurgery. The actual lens position can be determined from the vitreouslength and the center thickness of the IOL. The optical add power can becustomized based on at least one of: a corneal power, an axial length oran anterior chamber depth. The optical add power can be customized basedon a preferred reading distance.

The optical add power for implementations of a multifocal lens optimizedfor viewing objects at a maximum distance of 50 cm and having aspherical equivalent optical power less than or equal to 10 Diopters canbe between about 2.7 Diopter and about 3.4 Diopter.

The optical add power for implementations of a multifocal lens optimizedfor viewing objects at a maximum distance of 50 cm through the nearvision zone and having a spherical equivalent optical power greater than5 Diopter and less than or equal to 40 Diopters can be between about 2.5Diopter and about 3.4 Diopter.

The optical add power for implementations of a multifocal lens optimizedfor viewing objects at a maximum distance of 42 cm and having aspherical equivalent optical power less than or equal to 10 Diopters canbe between about 3.25 Diopter and about 4.0 Diopter, and

The optical add power for implementations of a multifocal lens optimizedfor viewing objects at a maximum distance of 42 cm through the nearvision zone and having a spherical equivalent optical power greater than10 Diopter and less than or equal to 50 Diopters can be between about3.0 Diopter and about 4.0 Diopter.

Another innovative aspect of this application is embodied in a kitcomprising a plurality of intraocular lenses for implantation in to theeye of a patient. The kit comprises a plurality of multifocal opticshaving a spherical equivalent optical power less than or equal to 50Diopters. Each of the plurality of multifocal optics comprise an opticaladd power that is optimized for viewing at one or more preferred nearand/or intermediate distances. For each preferred distance, theplurality of multifocal optics have an optical add power in a firstrange for spherical equivalent optical powers less than or equal to 10Diopters and an optical add power in a second non-overlapping range forspherical equivalent optical powers greater than 10 Diopter and lessthan or equal to 50 Diopters. The first range can be between 2.75Diopter and 4.0 Diopter. The second range can be between 2.25 Diopterand 2.75 Diopter. The preferred distance can be 50 cm or 42 cm. Theoptical add power of the plurality of multifocal optics optimized foreach preferred distance can be calculated using a formula that dependson a position of the intraocular lens when implanted in the eye of thepatient, a shape of the patient's eye, and the preferred readingdistance.

Another innovative aspect of this application contemplates a method ofmanufacturing an intraocular lens, the method comprising manufacturingan intraocular lens having a spherical equivalent power and a customizedoptical add power, wherein the customized optical add power is based onat least one of an ocular biometry of an individual, a position of theintraocular lens in the eye, or a preferred reading distance, andwherein ocular biometry comprises at least one of an axial length (AL)of the individual's eye, corneal power (K) or anterior chamber depth.

Another innovative aspect of this application contemplates a method ofdesigning and manufacturing a multifocal IOL that is customized for aparticular reading distance, wherein the add power differs depending onthe base power

Yet another innovative aspect of this application contemplates a methodof selecting the add power of an intraocular lens, the method comprisingdetermining a customized optical add power based on at least one of anocular biometry of an individual, a position of the intraocular lens inthe eye, or a preferred reading distance, and selecting from a range ofexisting IOLs an IOL that has an optical add power closest to thedetermined customized optical add power and a spherical equivalent powerclosest to a desired spherical equivalent power, wherein ocular biometrycomprises at least one of an axial length (AL) of the individual's eye,corneal power (K) or anterior chamber depth.

BRIEF DESCRIPTION OF THE DRAWINGS

The systems, methods and devices may be better understood from thefollowing detailed description when read in conjunction with theaccompanying schematic drawings, which are for illustrative purposesonly. The drawings include the following figures:

FIG. 1 illustrates an embodiment of a multifocal intraocular lens.

FIGS. 2-6 are graphs of customized optical add power for differentreading distance versus spherical equivalent power.

FIG. 7 is a flow chart of an example method of manufacturing amultifocal IOL having a base IOL power and a customized optical addpower.

FIG. 8 is a graphical representation of the elements of a computingsystem used to calculate a customized optical add power.

FIG. 9 illustrates a graph of optical add power for a multifocal IOL fordifferent spherical equivalent powers.

DETAILED DESCRIPTION

Presbyopic patients can benefit from multifocal lenses that can providevision correction for distance and near and/or intermediate vision. FIG.1 illustrates an embodiment of a multifocal intraocular lens 100comprising an optic 102 and a haptic 101. The optic 102 comprises aplurality of optical zones 103 that are configured to focus light fromdifferent distances onto the retina. The plurality of optical zones 103can comprise diffractive and/or refractive features that are configuredto focus light from different distances onto the retina.

Current multifocal intraocular lenses (IOLs) are offered in discrete addpowers. The discrete add powers are fixed (or constant) across theentire range of spherical equivalent powers provided by the IOL. Forexample, different IOLs configured to provide different sphericalequivalent power are configured to provide a fixed add power (e.g., 4.0Diopter, 2.75 Diopter, or 3.25 Diopter). The effect of the fixed addpower can be determined by transforming an add power in the IOL plane toan add power in the spectacle plane using a fixed ratio. As used hereinspherical equivalent power can refer to the base optical power of theIOL that provides distance vision correction. The spherical equivalentpower can also be referred to as the IOL power. The spherical equivalentpower can vary between −10 Diopter and 50 Diopter. For example, thespherical equivalent power can between 0 Diopter and 40 Diopter, orbetween 5 Diopter and 34 Diopter.

One study indicates that the near focal distance of an eye implantedwith a multifocal intraocular lens can depend on an effective lensposition (ELP) of the multifocal intraocular lens in the eye. The ELPcan depend on a variety of parameters including but not limited to axiallength, corneal power and, preoperative anterior chamber depth or acombination thereof. Another study indicates that the optimum distancethat provides an optimized near vision performance with a multifocal IOLthat is configured to provide a fixed add power (e.g., 4.0 Diopter) canvary depending on the ocular biometry (e.g., axial length, or anteriorchamber depth). For example, the optimum distance that provides anoptimized near vision performance with a multifocal IOL having a fixedadd power of 4.0 Diopter is about (i) 29.5 cm for patients withhyperopia, (ii) about 32.8 cm for emmetropes and (iii) about 34.5 cm forpatients with myopia. Thus, according to this study, the dioptric poweryielding the best near vision performance is substantially correlatedwith axial length and anterior chamber depth of the patient's eye.Accordingly, it may be advantageous to customize the add power of IOLsbased on a patient's ocular biometry, the placement of the IOL whenimplanted and/or preferred reading distance. Ocular biometry can includea variety of ocular parameters including but not limited to axial length(AL) of the eye, corneal power (K), vitreous length and/or anteriorchamber depth.

This application contemplates multifocal IOLs with optical add powerthat is customized for an individual patient. The customized optical addpower can depend on various parameters including but not limited to theposition of the IOL in the eye, axial length (AL) of the eye, cornealpower (K), anterior chamber depth, or a combination thereof. Theposition of the IOL in the eye can correspond to the ELP or the actuallens position (ALP). The ELP can be calculated using the Holladay,Hoffer Q or Haigis formula

The ALP can be determined in a variety of ways. For example, in onemethod, the ALP can be determined from a relationship between theanterior-chamber depth prior to the surgery and the actual IOL positionmeasured from the anterior cornea also referred to as anterior chamberdepth after the surgery. The relationship between the anterior-chamberdepth prior to the surgery and the anterior chamber depth after thesurgery can be linear. The anterior-chamber depth prior to the surgerycan be measured with anterior segment slit-lamp images. The anteriorchamber depth after the surgery can be measured with an anterior chamberOCT instrument. As another example, in another method, the ALP can bedetermined based on the post-operative vitreous length and the centerthickness of the implanted IOL.

The ELP can be determined from various IOL power calculation formulaethat are used currently. For example, ELP can be determined using theformulae and methods described in the articles from Holladay, Hoffer andHaigis mentioned above. However, this application also contemplates thedetermination of the ELP based on customized methods. Any combination ofELP and ALP determination methods can be used to optimize the opticaladd power that optimizes individual's near vision performance. Thecustomized add power can be calculated using the principles of paraxialoptics to determine the relationship between add power, ocular biometryand distance that provides the best near and/intermediate visionperformance.

For example, the customized optical add power in Diopters of amultifocal IOL for an individual can be calculated using equation 1below:

$\begin{matrix}{{{Add}\mspace{14mu}{power}} = {\frac{1.336}{\frac{1.336}{K} - \frac{{IOL}\mspace{14mu}{position}}{1000}} - \frac{1.336}{\frac{1.336}{K - {100/\frac{{reading}\mspace{14mu}{distance}}{\begin{bmatrix}{1 - {100/}} \\{{reading}\mspace{14mu}{distance}}\end{bmatrix}*0.012}}} - \frac{{IOL}\mspace{14mu}{position}}{1000}}}} & (1)\end{matrix}$

In equation (1) above, IOL position corresponds to ELP or ALP inmillimeters (mm) determined from any of the equations or methodsdescribed herein, K corresponds to the corneal power in Diopters,reading distance corresponds to the distance for best near visionperformance in centimeters (cm). The optical add power can be calculatedindependently from the calculation of the spherical equivalent power ofthe IOL. In contrast to current multifocal IOLs that are available, thecustomized optical add power of various embodiments of multifocal IOLscontemplated by this application is not constant for different sphericalequivalent power. Instead, the customized optical add power can varybased on the spherical equivalent power of the IOL as discussed belowwith reference to FIGS. 2-6 which illustrate graphs of customizedoptical add power for different reading distance versus sphericalequivalent power. A wide range of ocular biometries based on biometrydata sets that were previously analyzed were used to study the relationbetween add power and reading distance given by equation (1) above forthe ELP calculated by any of the various methods described herein. Tostudy the relation between add power and reading distance differentbiometry combinations were created with corneal power in a range between38 D to 45 D, axial length in a range between 20 mm to 30 mm andanterior chamber depth in a range between 2 mm to 4 mm

FIG. 2 shows the variation of the customized optical add power ascalculated by equation (1) represented by curve 201 with respect tospherical equivalent power (also referred to as IOL power) for a readingdistance of 50 cm. For each biometry combination, the ELP was calculatedaccording to the Haigis formula. This value was used for IOL position inequation (1) to calculate customized optical add power represented bycurve 201. The line 203 corresponds to a fixed optical add power ofabout 2.7 Diopters in the IOL plane which was calculated by translatingthe optical add power calculated in the spectacle plane for a readingdistance of 50 cm to the IOL plane by assuming a fixed ratio of 0.75.This method of calculating the optical add power represents the currentstate of the art to relate optical add power to reading distance. It isobserved from FIG. 2 that optical add power varies inversely tospherical equivalent power. Accordingly, optical add power is higher forlower spherical equivalent power. It is further observed from FIG. 2that the current state of the art underestimates the optical add powerfor eyes that require lower spherical equivalent power, such as, forexample, patients who have axial length longer than a normal averagehuman eye, who are typically myopic prior the cataract surgery. Someaverage human eyes can also require lower spherical equivalent power andthe current state of the art can underestimate the required optical addpower.

FIG. 3 illustrates the variation of the customized optical add power ascalculated by equation (1) represented by curve 301 with respect tospherical equivalent power (also referred to as IOL power) for a readingdistance of 42 cm. The line 303 corresponds to a fixed optical add powerof about 3.15 Diopters which was calculated by translating the opticaladd power calculated in the spectacle plane for a reading distance of 42cm to the IOL plane by assuming a fixed ratio of 0.75 in accordance withthe current state of the art. FIG. 4 illustrates the variation of thecustomized optical add power as calculated by equation (1) representedby curve 401 with respect to spherical equivalent power (also referredto as IOL power) for a reading distance of 33 cm. The line 403corresponds to a fixed optical add power of about 4.1 Diopters which wascalculated by translating the optical add power calculated in thespectacle plane for a reading distance of 33 cm to the IOL plane byassuming a fixed ratio of 0.75 in accordance with the current state ofthe art. The customized optical add power in FIGS. 3 and 4 werecalculated using equation (1) and the ELP per Haigis formula. Asdiscussed above with reference to FIG. 2, the customized optical addpower varies inversely with respect to the spherical equivalent power inFIGS. 3 and 4.

The IOL position can be calculated using other formulae and/or methodsdescribed herein. For example, the IOL position in equation (1) cancorrespond to the ELP calculated in accordance with the Hoffer Qformula. Curve 501 of FIG. 5 represents the customized optical add poweras calculated by equation (1) for a reading distance of 50 cm, whereinthe IOL position in equation (1) corresponds to the ELP calculated inaccordance with the Hoffer Q formula. Curve 503 of FIG. 5 corresponds tothe fixed optical add power for a reading distance of 50 cm calculatedin accordance with the current state of art. It is observed from FIG. 5that customized optical add power obtained using ELP calculated inaccordance with the Hoffer Q formula varies inversely with respect tothe spherical equivalent power.

FIG. 6 illustrates the variation of the customized optical add power(represented by curve 601) as calculated by equation (1) for a readingdistance of 50 cm, wherein the IOL position in equation (1) correspondsto the ELP calculated in accordance with the Holladay I formula withrespect to the spherical equivalent power. It is observed from FIG. 6that the optical add power varies for different biometry configurations.When the Holladay I formula is used to determine the ELP, the variationof the optical add power with IOL power is different from the variationof the optical add power with IOL power when the ELP is determined usingHoffer Q or Haigis formulae.

One or more multifocal IOLs having a base IOL power (also referred to asspherical equivalent power) and a customized optical add power can bemanufactured using a variety of IOL manufacturing methods. FIG. 7 is aflowchart illustrating an example method of manufacturing. The methodcomprises determining ocular biometry of an individual as shown in block701. The method further comprises determining the position of the IOLwhen implanted in the individual's eye as shown in block 703. Theposition of the IOL when implanted in the eye can be calculated usingany of the methods described herein and it can be either the actual lenspositon (ALP), the effective lens positon (ELP) or a combination ofthese. The method further comprises determining a preferred readingdistance for the individual as shown in block 705. The determination ofthe ocular biometry, position of the IOL when implanted in theindividual's eye and the preferred reading distance need not beperformed in the order illustrated in FIG. 7. In various cases, thedetermination of the ocular biometry, position of the IOL when implantedin the individual's eye and the preferred reading distance can beperformed in a different order or simultaneously. The method furthercomprises calculating a customized optical add power for the individualbased on the determined ocular biometry, position of the IOL whenimplanted in the individual's eye and the preferred reading distance asshown in block 707. The calculation can be performed using a formula,such as, for example, the formula of equation (1).

An electronic processing system configured to execute instruction storedin a non-transitory computer storage medium can be employed to calculatethe optimized optical add power. FIG. 8 illustrates an example of anelectronic processing system 800 that can be used to calculate thecustomized optical add power. The electronic processing system 800comprises an electronic hardware processor 802 and a computer readablememory 804 coupled to the electronic hardware processor 802. Thecomputer readable memory 804 has stored therein an array of orderedvalues 808 and sequences of instructions 810 which, when executed by theelectronic hardware processor 802, cause the electronic hardwareprocessor 802 to perform certain functions or execute certain modules.For example, a module to calculate the customized optical add power canbe executed. The electronic hardware processor 802 can be configured toreceive the determined ocular biometry, position of the IOL whenimplanted in the individual's eye and the preferred reading distanceelectronically. In some embodiments, various ophthalmic instruments thatare used to determine ocular biometry and the preferred reading distancecan be in electronic communication with the electronic hardwareprocessor 802.

The array of ordered values 808 may comprise, for example, one or moreocular dimensions of one or more human eyes, a desired refractiveoutcome, parameters of an eye model based on one or more characteristicsof at least one eye, and data related to an IOL or set of IOLs such as apower, an aspheric profile, and/or a lens plane. In some embodiments,the sequence of instructions 810 includes determining the position of anIOL when implanted in the individual's eye and performing one or morecalculations to determine a base IOL power and/or a customized opticaladd power that provides optimal near and/or intermediate and distancevision correction. The optimal near and/or intermediate and distancevision correction can be based on equation 1. In some embodiments, thesequence of instruction 810 can be configured to iteratively optimizevarious parameters of the IOL including but not limited to base IOLpower and the customized optical add power to optimize near and/orintermediate and distance vision correction. The system can also beprogrammed so that it accepts postoperative outcomes. For any givenreading distance, as well as the postoperative IOL position andbiometry, the system can be configured to calculate the optical addpower that is customized to the patient. The calculation can beperformed in an iterative fashion, so that the system can adjust analgorithm used to calculate the optical add power to improve accuracyfor a wide range of optical biometries.

The electronic processing system 800 may be a general purpose desktop orlaptop computer or may comprise hardware specifically configuredperforming the desired calculations. In some embodiments, the electronicprocessing system 800 is configured to be electronically coupled toanother device such as a phacoemulsification console or one or moreinstruments for obtaining measurements of an eye or a plurality of eyes.In other embodiments, the electronic processing system 800 is a handhelddevice that may be adapted to be electronically coupled to one of thedevices just listed. In yet other embodiments, the electronic processingsystem 800 is, or is part of, refractive planner configured to provideone or more suitable intraocular lenses for implantation based onphysical, structural, and/or geometric characteristics of an eye, andbased on other characteristics of a patient or patient history, such asthe age of a patient, medical history, history of ocular procedures,life preferences, and the like.

Generally, the instructions of the electronic processing system 800 willinclude elements of the method 700 and/or parameters and routines forperforming calculations based on one or more formulae to determine atleast one of a position of the IOL when implanted in the eye, customizedoptical add power, base IOL power or higher order aberrationcorrections.

In certain embodiments, the electronic processing system 800 includes oris part a phacoemulsification system, laser treatment system, opticaldiagnostic instrument (e.g., autorefractor, aberrometer, and/or cornealtopographer, or the like). For example, the computer readable memory 804may additionally contain instructions for controlling the handpiece of aphacoemulsification system or similar surgical system. Additionally oralternatively, the computer readable memory 804 may additionally containinstructions for controlling or exchanging data with an autorefractor,aberrometer, tomographer, and/or topographer, or the like.

In some embodiments, the electronic processing system 800 includes or ispart of a refractive planner. The refractive planner may be a system fordetermining one or more treatment options for a subject based on suchparameters as patient age, family history, vision preferences (e.g.,near, intermediate, distant vision), activity type/level, past surgicalprocedures.

This application also contemplates manufacturing An IOL kit comprisingat least two multifocal IOLs, each having a base IOL power and acustomized add power. The customized add power can be determined basedon an individual's near and or intermediate vision requirements (e.g., apreferred reading distance), the individual's ocular biometry and/or theposition of the IOL when implanted in the eye as discussed herein. Theat least two multifocal IOLs can be manufactured according to thevarious manufacturing methods described herein.

FIG. 9 illustrates the selection of the add power from customizedcalculations for a standard multifocal IOL (e.g., TECNIS® multifocalIOL) for various base IOL powers. The standard multifocal IOL can havedifferent fixed optical add powers (e.g., 2.75 D, 3.25 D and 4.00 D inthe IOL plane). The customized optical add power was calculated usingequation (1) above, wherein the IOL position corresponds to ELPdetermined using the Haigis formula for a preferred reading distance of50 cm for a wide range of ocular biometries. These configurations werethe same as used in the examples above. As noted from FIG. 9, theselection of the add power for a particular reading distance (i.e. 50cm) varies depending on the IOL power. For base IOL powers less than orequal to about 10 Diopters the add power closer to the custom add powerfor a 50 cm reading distance has a first value of about 3.25 Diopters.For a base power greater than 15 D, the add power closer to the customadd power for a 50 cm reading distance has a second value of about 2.75Diopters. For base powers between 10 D and 15 D the add power closer tothe custom add power varies between 2.75 D and 3.25 D, depending onparticular eye's biometry.

For other embodiments of IOLs, the selection of the add power fromcustomized optical add power for base IOL powers less than or equal to athreshold optical power can be in a first range and the customizedoptical add power for base IOL powers greater than or equal to thethreshold optical power can be in a second range. The threshold opticalpower can be greater than or equal to about 10 Diopters, greater than orequal to about 12.5 Diopters, greater than or equal to about 15Diopters, less than or equal to about 20 Diopters, less than or equal toabout 25 Diopters, or any value in a range/sub-range defined by thesevalues. Furthermore, different thresholds can be defined depending onthe available add power steps.

The first range and the second range of optical add power can benon-overlapping. In various embodiments, the first range of optical addpowers can be greater than or equal to about 2.9 Diopters and less thanor equal to about 5.0 Diopters, such as for example, greater than orequal to about 3.0 Diopters and less than or equal to about 4.5Diopters, greater than or equal to about 3.0 Diopters and less than orequal to about 4.25 Diopters, greater than or equal to about 3.0Diopters and less than or equal to about 4.0 Diopters, greater than orequal to about 3.0 Diopters and less than or equal to about 3.75Diopters, greater than or equal to about 3.0 Diopters and less than orequal to about 3.50 Diopters, greater than or equal to about 3.0Diopters and less than or equal to about 3.25, greater than or equal toabout 3.25 Diopters and less than or equal to about 4.5 Diopters,greater than or equal to about 3.25 Diopters and less than or equal toabout 4.25 Diopters, greater than or equal to about 3.25 Diopters andless than or equal to about 4.0 Diopters, greater than or equal to about3.25 Diopters and less than or equal to about 3.75 Diopters, greaterthan or equal to about 3.25 Diopters and less than or equal to about3.50, greater than or equal to about 3.50 Diopters and less than orequal to about 4.5 Diopters, greater than or equal to about 3.50Diopters and less than or equal to about 4.25 Diopters, greater than orequal to about 3.50 Diopters and less than or equal to about 4.0Diopters, greater than or equal to about 3.50 Diopters and less than orequal to about 3.75 Diopters, greater than or equal to about 3.75Diopters and less than or equal to about 4.5 Diopters, greater than orequal to about 3.75 Diopters and less than or equal to about 4.25Diopters, greater than or equal to about 3.75 Diopters and less than orequal to about 4.0 Diopters, greater than or equal to about 4.0 Dioptersand less than or equal to about 4.5 Diopters, greater than or equal toabout 4.0 Diopters and less than or equal to about 4.25 Diopters,greater than or equal to about 4.25 Diopters and less than or equal toabout 4.5 Diopters, Diopters, or any value in a range/sub-range definedby these values.

In various embodiments, the first range of optical add powers can begreater than or equal to about 1.5 Diopters and less than or equal toabout 3.25 Diopters, such as for example, greater than or equal to about1.5 Diopters and less than or equal to about 3.00 Diopters, greater thanor equal to about 1.5 Diopters and less than or equal to about 2.75Diopters, greater than or equal to about 1.5 Diopters and less than orequal to about 2.5 Diopters, greater than or equal to about 1.5 Dioptersand less than or equal to about 2.25 Diopters, greater than or equal toabout 1.65 Diopters and less than or equal to about 3.25 Diopters,greater than or equal to about 1.65 Diopters and less than or equal toabout 3.00 Diopters, greater than or equal to about 1.65 Diopters andless than or equal to about 2.75 Diopters, greater than or equal toabout 1.65 Diopters and less than or equal to about 2.5 Diopters,greater than or equal to about 1.65 Diopters and less than or equal toabout 2.25 Diopters, greater than or equal to about 1.75 Diopters andless than or equal to about 3.25 Diopters, greater than or equal toabout 1.75 Diopters and less than or equal to about 3.00 Diopters,greater than or equal to about 1.75 Diopters and less than or equal toabout 2.75 Diopters, greater than or equal to about 1.75 Diopters andless than or equal to about 2.5 Diopters, greater than or equal to about1.75 Diopters and less than or equal to about 2.25 Diopters, greaterthan or equal to about 2.00 Diopters and less than or equal to about3.25 Diopters, greater than or equal to about 2.00 Diopters and lessthan or equal to about 3.00 Diopters, greater than or equal to about2.00 Diopters and less than or equal to about 2.75 Diopters, greaterthan or equal to about 2.00 Diopters and less than or equal to about 2.5Diopters, greater than or equal to about 2.00 Diopters and less than orequal to about 2.25 Diopters, or any value in a range/sub-range definedby these values.

CONCLUSION

The systems and methods described herein can be used to design andmanufacture multifocal IOLs that are customized to an individual'socular biometrics, placement of the IOL in the individual's eye and theindividual's near distance vision requirements (e.g., preferred readingdistance, preferred reading position, length of arms, etc.). The addpower of a multifocal IOL designed and manufactured according to theconcepts discussed herein is optimized for an individual to view objectsat a preferred distance in the near and/or intermediate vision zone.This is in contrast to existing multifocal IOLs that provide a fixedoptical add power without taking into consideration an individual'socular biometry and/or preferred reading distance.

The systems and methods described herein can be used to design andmanufacture multifocal IOLs that are customized for a particular readingdistance, wherein the add power differs depending on the base power. Inthat way, the spherical equivalent IOL power range can be designed andmanufactured to provide with a particular reading distance instead ofwith a particular add power in the IOL plane.

The systems and methods described herein can be used to predict theoptical performance of one or more lenses or lens models for adetermined ocular biometry and a preferred reading distance. This can beadvantageous to select one of a plurality of multifocal IOLs from an IOLkit that would optimize both near and/or intermediate and distancevision for an individual. For example, the optimum reading distance canbe determined using a modified version of equation (1) from a knownoptical add power, ocular biometry of an individual and the position ofthe IOL in the eye. Thus, it is possible to predict the reading distanceat which a multifocal IOL with a known optical add power would providethe best near vision performance for an individual.

The systems and methods described herein can be used to calculate theadd power of a particular add on lens, sulcus lens, phakic lens, contactlens or laser treatment. The systems and methods described herein can beused to customize monovision outcomes. For example, a combination of abase IOL power and a customized optical add power can be used to obtaina desired monovision outcome for near or intermediate vision. Acombination of a base IOL power and optical zones that provide differentcustomized optical add powers can be used to improve visual outcomes fordifferent distances in far, intermediate and near vision zones. Thesystems and methods described herein can be used to design andmanufacture toric lenses configured to provide astigmatism correctionbased on an individual's ocular biometry, position of the IOL in theeye. In some embodiments of such toric lenses, the toric power steps candepend on the base power.

The above presents a description of the best mode contemplated ofcarrying out the concepts disclosed herein, and of the manner andprocess of making and using it, in such full, clear, concise, and exactterms as to enable any person skilled in the art to which it pertains tomake and use the concepts described herein. The systems, methods anddevices disclosed herein are, however, susceptible to modifications andalternate constructions from that discussed above which are fullyequivalent. Consequently, it is not the intention to limit the scope ofthis disclosure to the particular embodiments disclosed. On thecontrary, the intention is to cover modifications and alternateconstructions coming within the spirit and scope of the presentdisclosure as generally expressed by the following claims, whichparticularly point out and distinctly claim the subject matter of theimplementations described herein.

Although embodiments have been described and pictured in an example formwith a certain degree of particularity, it should be understood that thepresent disclosure has been made by way of example, and that numerouschanges in the details of construction and combination and arrangementof parts and steps may be made without departing from the spirit andscope of the disclosure as set forth in the claims hereinafter.

As used herein, the term “processor” refers broadly to any suitabledevice, logical block, module, circuit, or combination of elements forexecuting instructions. For example, the electronic hardware processor802 can include any conventional general purpose single- or multi-chipmicroprocessor such as a Pentium® processor, a MIPS® processor, a PowerPC® processor, AMD® processor, ARM processor, or an ALPHA® processor. Inaddition, the electronic hardware processor 802 can include anyconventional special purpose microprocessor such as a digital signalprocessor. The various illustrative logical blocks, modules, andcircuits described in connection with the embodiments disclosed hereincan be implemented or performed with a general purpose processor, adigital signal processor (DSP), an application specific integratedcircuit (ASIC), a field programmable gate array (FPGA), or otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, or any combination thereof designed to perform thefunctions described herein. The electronic hardware processor 802 can beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

Computer readable memory 804 can refer to electronic circuitry thatallows information, typically computer or digital data, to be stored andretrieved. Computer readable memory 804 can refer to external devices orsystems, for example, disk drives or solid state drives. Computerreadable memory 804 can also refer to fast semiconductor storage(chips), for example, Random Access Memory (RAM) or various forms ofRead Only Memory (ROM), which are directly connected to thecommunication bus or the electronic hardware processor 802. Other typesof memory include bubble memory and core memory. Computer readablememory 804 can be physical hardware configured to store information in anon-transitory medium.

Methods and processes described herein may be embodied in, and partiallyor fully automated via, software code modules executed by one or moregeneral and/or special purpose computers. The word “module” can refer tologic embodied in hardware and/or firmware, or to a collection ofsoftware instructions, possibly having entry and exit points, written ina programming language, such as, for example, C or C++. A softwaremodule may be compiled and linked into an executable program, installedin a dynamically linked library, or may be written in an interpretedprogramming language such as, for example, BASIC, Perl, or Python. Itwill be appreciated that software modules may be callable from othermodules or from themselves, and/or may be invoked in response todetected events or interrupts. Software instructions may be embedded infirmware, such as an erasable programmable read-only memory (EPROM). Itwill be further appreciated that hardware modules may comprise connectedlogic units, such as gates and flip-flops, and/or may comprisedprogrammable units, such as programmable gate arrays, applicationspecific integrated circuits, and/or processors. The modules describedherein can be implemented as software modules, but also may berepresented in hardware and/or firmware. Moreover, although in someembodiments a module may be separately compiled, in other embodiments amodule may represent a subset of instructions of a separately compiledprogram, and may not have an interface available to other logicalprogram units.

In certain embodiments, code modules may be implemented and/or stored inany type of computer-readable medium or other computer storage device.In some systems, data (and/or metadata) input to the system, datagenerated by the system, and/or data used by the system can be stored inany type of computer data repository, such as a relational databaseand/or flat file system. Any of the systems, methods, and processesdescribed herein may include an interface configured to permitinteraction with users, operators, other systems, components, programs,and so forth.

What is claimed is:
 1. An intraocular lens for implantation into the eyeof a patient, the intraocular lens comprising: a multifocal optic havinga spherical equivalent optical power less than or equal to 50 Diopters,the multifocal optic comprising an optical add power customized for apatient's visual needs, wherein the optical add power is determinedbased on a position of the intraocular lens when implanted in the eye ofthe patient, and a parameter of the patient's eye.
 2. The intraocularlens of claim 1, wherein the position of the intraocular lens whenimplanted in the eye of the patient is the effective lens position. 3.The intraocular lens of claim 1, wherein the position of the intraocularlens when implanted in the eye of the patient is the actual lensposition.
 4. The intraocular lens of claim 1, wherein the parameter ofthe patient's eye is at least one of: a corneal power, an axial lengthor an anterior chamber depth.
 5. The intraocular lens of claim 1,wherein the optical add power is further determined based on a preferredreading distance.
 6. The intraocular lens of claim 1, wherein theoptical add power for a multifocal lens optimized for viewing objects ata maximum distance of 50 cm and having a spherical equivalent opticalpower less than or equal to 10 Diopters is between about 2.7 Diopter andabout 3.4 Diopter.
 7. The intraocular lens of claim 1, wherein theoptical add power for a multifocal lens optimized for viewing objects ata maximum distance of 42 cm through the near vision zone and having aspherical equivalent optical power greater than 10 Diopter and less thanor equal to 50 Diopters is between about 3.0 Diopter and about 4.0Diopter.
 8. A kit comprising a plurality of intraocular lenses forimplantation into an eye of a patient, the kit comprising: a pluralityof multifocal optics having a spherical equivalent optical power lessthan or equal to 50 Diopters, wherein the plurality of multifocal opticseach of which comprises an optical add power that is determined based ona position of an intraocular lens when implanted in the eye of thepatient and is optimized for viewing at one or more preferred nearand/or intermediate distances, wherein for each preferred distance, theplurality of multifocal optics have a first optical add power range in afirst range for spherical equivalent optical powers less than or equalto 10 Diopters, and the plurality of multifocal optics have a secondoptical add power range in a second non-overlapping range for sphericalequivalent optical powers greater than 10 Diopter and less than or equalto 50 Diopters.
 9. The kit of claim 8, wherein the first optical addpower range is between 2.75 Diopter and 4.0 Diopter.
 10. The kit ofclaim 8, wherein the second range is between 2.25 Diopter and less than2.75 Diopter.
 11. The kit of claim 8, wherein the preferred distance is50 cm or 42 cm.
 12. The kit of claim 8, wherein the optical add power ofthe plurality of multifocal optics optimized for each preferred distanceis calculated using a formula that depends on a position of theintraocular lens when implanted in the eye of the patient, a shape ofthe patient's eye, and the preferred reading distance.